Answer:
1.10 × 10⁻¹² m
General Formulas and Concepts:
<u>Chemistry - Atomic Structure</u>
Speed of Light = Wavelength times Frequency
Explanation:
<u>Step 1: Define</u>
ν = 2.73 × 10²⁰ Hz
<u>Step 2: Find wavelength</u>
3.0 × 10⁸ m/s = λ(2.73 × 10²⁰ Hz)
λ = 1.0989 × 10⁻¹² m
<u>Step 3: Check</u>
<em>We are given 3 sig figs. Follow sig fig rules.</em>
1.0989 × 10⁻¹² m ≈ 1.10 × 10⁻¹² m
Answer:
its particles slow down and come closer together.
Iodine has 7 valence electrons. It needs therefore only 1 electron to be stable this is why it is so reactive.
Answer: The correct option is C ( is very hard and burns cleanly).
Explanation:
COAL is a form of rock that is made up of mostly carbon amongst other elements which includes sulphur, nitrogen, hydrogen and oxygen. There are different types of coal which include:
--> anthracite ( 90% carbon)
--> bituminous coal ( 70-90% carbon)
--> lignite ( 60- 70% carbon) and
--> peat (60 % carbon).
Anthracite is the type of coal that contains the highest carbon content ( 90% carbon). This makes it very hard and is often a times referred to as HARD COAL. Anthracite is a higher quality coal for domestic and open fire heating. This is because it contains less impurities than other type of coal and thereby making it to BURN CLEANLY avoiding atmospheric pollution.
